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    1 Comment for this article
    Why water?
    David Saltissi, MBBS, MD( LONDON) | Chermside Dialysis Centre
    There is nothing magic about pure water, indeed it is the most dangerous hypotonic fluid you can ingest and in excess may be fatal (viz water intoxication or poisoning!!) I am sure the authors would have got the same and probably better result with 1.5l general fluid rather than water! Did they check for hyponatraemia and other electrolyte deficiencies, postural hypotension, nocturia with sleep loss, change in GFR, symptomatic muscle cramps, oedema etc
    Original Investigation
    November 2018

    Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections: A Randomized Clinical Trial

    Author Affiliations
    • 1Department of Medicine, School of Medicine, University of Miami, Miami, Florida
    • 2Danone Nutricia Research, Palaiseau, France
    • 3Service des Explorations Fonctionnelles Physiologiques, CHU de Toulouse, Université Paul Sabatier, Toulouse, France
    • 4Department of Urology, University of Texas Southwestern Medical Center, Dallas
    JAMA Intern Med. 2018;178(11):1509-1515. doi:10.1001/jamainternmed.2018.4204
    Key Points

    Question  Does increased daily water intake prevent cystitis in premenopausal women experiencing recurrent cystitis who drink low volumes of total fluid daily?

    Findings  In this randomized clinical trial of 140 premenopausal women experiencing recurrent cystitis who report drinking less than 1.5 L of total fluid daily, cystitis episodes were significantly less frequent in women who drank more water for 12 months compared with women who maintained their usual fluid intake.

    Meaning  Increasing daily water intake protects against recurrent cystitis in premenopausal women experiencing recurrent cystitis who drink low volumes of total fluid daily.


    Importance  Increased hydration is often recommended as a preventive measure for women with recurrent cystitis, but supportive data are sparse.

    Objective  To assess the efficacy of increased daily water intake on the frequency of recurrent cystitis in premenopausal women.

    Design, Setting, and Participants  Randomized, open-label, controlled, 12-month trial at a clinical research center (years 2013-2016). Among 163 healthy women with recurrent cystitis (≥3 episodes in past year) drinking less than 1.5 L of fluid daily assessed for eligibility, 23 were excluded and 140 assigned to water or control group. Assessments of daily fluid intake, urinary hydration, and cystitis symptoms were performed at baseline, 6- and 12-month visits, and monthly telephone calls.

    Interventions  Participants were randomly assigned to drink, in addition to their usual fluid intake, 1.5 L of water daily (water group) or no additional fluids (control group) for 12 months.

    Main Outcomes and Measures  Primary outcome measure was frequency of recurrent cystitis over 12 months. Secondary outcomes were number of antimicrobial regimens used, mean time interval between cystitis episodes, and 24-hour urinary hydration measurements.

    Results  The mean (SD) age of the 140 participants was 35.7 (8.4) years, and the mean (SD) number of cystitis episodes in the previous year was 3.3 (0.6). During the 12-month study period, the mean (SD) number of cystitis episodes was 1.7 (95% CI, 1.5-1.8) in the water group compared with 3.2 (95% CI, 3.0-3.4) in the control group, with a difference in means of 1.5 (95% CI, 1.2-1.8; P < .001). Overall, there were 327 cystitis episodes, 111 in the water group and 216 in the control group. The mean number of antimicrobial regimens used to treat cystitis episodes was 1.9 (95% CI, 1.7-2.2) and 3.6 (95% CI, 3.3-4.0), respectively, with a difference in means of 1.7 (95% CI, 1.3-2.1; P < .001). The mean time interval between cystitis episodes was 142.8 (95% CI, 127.4-160.1) and 84.4 (95% CI, 75.4-94.5) days, respectively, with a difference in means of 58.4 (95% CI, 39.4-77.4; P < .001). Between baseline and 12 months, participants in the water group, compared with those in the control group, had increased mean (SD) urine volume (1.4 [0.04] vs 0.1 [0.04] L; P < .001) and voids (2.4 [0.2] vs −0.1 [0.2]; P < .001) and decreased urine osmolality (−402.8 [19.6] vs −24.0 [19.5] mOsm/kg; P < .001).

    Conclusions and Relevance  Increased water intake is an effective antimicrobial-sparing strategy to prevent recurrent cystitis in premenopausal women at high risk for recurrence who drink low volumes of fluid daily.

    Trial Registration  ClinicalTrials.gov identifier: NCT02444975